Method for cleaning small parts

ABSTRACT

A process and apparatus for cleaning metal parts comprising introducing the metal part into an enclosure which has sufficient volume to enable the part to alternately enter a vapor zone and a liquid zone each within the enclosure, while the part is freely moving within a confined area.

2,161,511 12/1937 Dinley.....

United States Patent [72] Inventors George T. liittel Midland; 2,162,656 6/1939 Warrington Thomas I. Rozek, Bay City, both of Mich. 2,163,276 6/ 1939 Fritzsche et al [21] Appl. No. 749,123 2,280,811 4/ 1942 Edhofer et al. [22] Filed July 31, 1968 2,692,603 10/1954 Foote [45] Patented Oct. 26, 1971 2,808,064 10/ 1957 Kearney [73] Assignee The Dow Chemical Company 2,865,145 12/1958 Lans.........

Midland, Mich. 3,019,800 2/1962 Rand 3,096,774 7/1963 Rand 3,238,065 3/1966 Fullhart.................... [54] METHOD FOR CLEANING SMALL PARTS Primary Examiner-Moms 0. Wolk l Clalm, 2 Drawing Figs.

Assistant Examiner-Barry S. Richman Attorneys-Griswold and Burdick and Glwynn R. Baker ABSTRACT: A process and apparatus for cleaning metal parts comprising introducing the metal part into an enclosure which has sufficient volume to enable the part to alternately enter a vapor zone and a liquid zone each within the enclosure, while the part is freely moving within a confined area.

m O. s MMMZM m xn 5 l4 b25 3 8 0 IL 1 0% l B1 M 2 2 "B 1 "4 "2 mm s "m m- :0 T w n "4 N n "3 "u L ""2 E u "M mu T L T 1 mm m WM T: m E A TM mm mm m n W4 nw "3 n H m mm "0 n N um I hu W w s m n U IF '01 1 ll 1 1 2 l 6 METHOD FOR CLEANING SMALL PARTS BACKGROUND OF INVENTION At least several hundred patents and probably an equal number of publications describe processes and equipment for cleaning metal parts. These processes and equipment range from the simple open-topped vapor degreaser to the complex enclosed continuous degreasers which contain both vapor and liquid zones. Many of the industrial applications of processes and machines are specifically designed to clean a particular shape as for example screws, nails, gears, or the like.

It is an object of the present invention to design a general purpose small parts degreaser which effectively and efficiently will clean small parts regardless of shape. This and other objects will become apparent to those skilled in the art to which the invention pertains from the following specification and the accompaning drawings.

BRIEF DESCRIPTION OF INVENTION In accordance with the present invention the process comprises (l) confining the part or parts to be cleaned in a chamber which admits fluid into and out there of freely, (2) introducingthis chamber and parts into a tank which contains both a volatile liquid and its vapors, (3) positioning said chamber within said tank so that upon rotation, about one-half of the chamber is in the liquid while the other half is in the vapors above the liquid, (4) rotating the chamber thus to bring the parts alternately into the liquid then into the vapor while tumbling the part within the chamber, (5) raising the chamber so that it is entirely in the vapor zone, while tumbling, and (6) withdrawing the chamber completely from said tank into the surrounding atmosphere. The result of such a process is an excellent cleaning by removal of the grease, oil, accumulated fines and chips and general dirt which have accumulated on parts during processing. The alternate dunking" into the liquid and withdrawal into the vapor zone provides a liquid washing effect as the part or parts passed into the liquid and a vapor condensation washing effect as the part passes through the vapor. The final step insures the surface of the part is at least at the vapor temperature prior to withdrawal into the ambient atmosphere thus eliminating liquid drag-out.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail with reference to the apparatus as shown in the drawings, particularly FIG. 1.

One embodiment of the apparatus of the present invention, as illustrated in FIG. -1, comprises a tank I of generally rectangular shape, although the particular shape may vary and is not critical. Within the tank 1 is a solvent condensate collection trough 2 which extends about the inner periphery of the tank 1. Similarly, extending about the inner periphery of tank I and directly above the solvent-condensate-collecting trough 2 is a series of condensing tubes or pipes 3. The tubes 3 are designed to carry cold water and hereinafter will be referred to as cooling coils 3. The lower part 4 of tank I may take any shape convenient for easy removal of sludge, and preferably is coneshaped, as shown. The lower part 4 is provided with a liquid outlet 6 from which the liquid solvent which is contained within the tank 1 may be withdrawn. In close proximity to the bottom of the tank 1 and following generally the contour of the tank bottom configuration 4 is a wire mesh or screen 7 which prevents large chips, which come in with a part and are dislodged during the cleaning process, from entering the outlet 6. Located in the lower portion 4 of tank I along each side or if round or domeshaped about the periphery of the tank 1, are heating units 8 which are accessible through clean-out plates 9. A solvent inlet or fill line 10 is provided through the wall 11 of tank I at a position sufficiently above the tank'lower portion 4 to enable the liquid or solvent in the tank to be charged to the appropriate depth, indicated as I0.

The parts-handling means l2 and the mechanical means 13 for movement of the parts-handling means 12 are next descn d. The details of these mechanisms are shown in FIG.

2. The materials-handling means 12 comprises a framework 14 which has a generally rectangular configuration. The framework 14 has braces 15 and 16 extending diagonally across the frame 14 to insure stability of the framework. The upper area of the frame 14 is covered with a wire mesh 17. Slidably engageable into the framework 14 is a rectangular wire basket l8 which fits closely and matingly into said framework 14.

The mechanical means 13 for moving the materials-handling means 12 is also illustrated in FIG. 2. The mechanical means 13 comprises a shaft 20 fixedly attached to the center of framework 14 so that the rotation of the shaft 20 rotates the framework 14. The shaft 20 is provided with bearings (not shown) to support it and framework 14 when the framework 14 is loaded with parts. The bearing surfaces are positioned on a frame 21. A spur car 22 mounted on shaft 20 meshes with worm gear 23 on worm shaft 24. Worm shaft 24 is driven by a drive train (not shown). Frame 21 extends upwardly to meet and attach to horizontal frame 25 which is connected to a motivating source such as hydraulic ram 26. This mechanism constitutes the mechanical means 13 to move the handling means 12 vertically to various stations.

We claim: 1

l. A process for cleaning parts which comprises confining the parts to be cleaned within an open-work chamber, introducing the chamber into a liquid within a tank which contains a zone of a volatilizable liquid and a zone of vapors of said liquid; rotating the chamber in a manner to alternately bring said chamber and its parts into the liquid then into the vapors above the liquid, raising said chamber to a height within said tank whereat the entire chamber is in the vapor zone, rotating said chamber within said vapor zone until the surface of said parts have attained the temperature of said vapor, withdrawing said chamber into the ambient atmosphere, and removing said parts. 

